In the last few decades, the market for wireless communications devices has grown by orders of magnitude, fueled by the use of portable devices, and increased connectivity and data transfer between all manners of devices. Digital switching techniques have facilitated the large scale deployment of affordable, easy-to-use wireless communication networks. Furthermore, digital and radio frequency (RF) circuit fabrication improvements, as well as advances in circuit integration and other aspects have made wireless equipment smaller, cheaper, and more reliable. Wireless communication can operate in accordance with various standards such as IEEE 802.11x, Bluetooth, global system for mobile communications (GSM), code division multiple access (CDMA). As increased data throughput and other developments occur, updates and new standards are constantly being developed for adoption.
LTE is a standard for wireless communication. LAA-LTE (Licensed Assisted Access-LTE, also called LTE-LAA, LAA, LTE-U, LTE Unlicensed or unlicensed LTE) generally makes use of an unlicensed spectrum (e.g., a spectrum not reserved for a particular company, network, etc.) in a wireless network. Interference can occur when operating, transmitting, and/or receiving messages in the unlicensed spectrum.
LTE-Wireless Local Area Network (WLAN) Radio Level Integration and Interworking Enhancement (3GPP RP-151114) can enhance communication network-based WLAN offloading by improving user quality of experience and network utilization and by providing more control to operators.
Solutions are proposed using the work done in 3GPP Release 12 for Small Cell Enhancement Dual Connectivity. Both User Plane solution 2C (Bearer Switch) and solution 3C (Bearer Split) are starting points for aggregating user plane traffic over both licensed and unlicensed spectrum. The data traffic transmitted over WLAN is transported as Packet Data Convergence Protocol Protocol Data Units (PDCP PDUs). This results in the end point in the terminal device being the PDCP entity of the cellular protocol stack for both a bearer split and a bearer switch.
LTE-WLAN Radio Access Network (RAN) Level Integration Supporting Legacy WLAN is intended to define a radio access network (RAN) based LTE-WLAN aggregation solution at a bearer level which addresses the legacy WLAN deployment scenarios. The solution uses Internet Protocol Security (IPSec) transport of the IP payloads associated with a Data Radio Bearer (DRB). An IPSec tunnel is built over WLAN using both user equipment and an evolved node B (eNB) as anchor points. A DRB is transported over one access point at a time, either cellular or WLAN, although the terminal may have access to both.